Cumberland Azalea Rhododendron cumberlandense

Cumberland azalea is a woody, deciduous shrub in the Ericaceae (blueberry) family. It is native to the southeastern United States, specifically the Cumberland Plateau of Kentucky south to Tennessee and the mountains of Georgia, Alabama, and North Carolina. It grows 3 to 7 feet tall. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree.

This azalea prefers full sun in the north and partial shade in the south and will need supplemental water during a drought. Plant in organically-rich, moist, well-drained, acidic soil and only prune lightly. It is best propagated from seed as it is difficult to start from cuttings.

Flowers are showy in orange or pink colors and bloom from June to July after the plant has leafed out which is later than other azaleas. Prune rhododendrons and azaleas after they bloom to preserve the current season's bloom, and allow time for the plant to produce flower buds for next year's bloom.

Use in woodland and native gardens as a specimen or in small groups. It works well planted on slopes or banks.  Since it is attractive to hummingbirds, butterflies, and moths it makes a good border shrub in butterfly and pollinator gardens.  It is a host plant for the larvae of the Rhododendron borer moth (Synanthedon rhododendri) as well as the Azalea caterpillar (Datana major).

Quick ID Hints:

• Green ovate leaves 1 to 3 inches in length
• Hairs may be present on the leaf margins
• Bark is brownish gray smooth to vertically furrowed and shredding 

Insects, Diseases, and Other Plant Problems: While azaleas and rhododendrons remain very popular for landscape use, many cultivars are susceptible to Phytophthora root rot–this leads to leaf loss, reduced vigor, branch dieback, and wilting. Implement good cultural practices first, such as improving drainage with organic matter or berms and avoiding overwatering or overfertilization. However, if you have a site with a history of this disease, consider planting one of the root rot-resistant alternative species. For suitable alternatives, see this video created by Charlotte Glen as part of the Plants, Pests, and Pathogens series.

The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases of rhododendron.  

VIDEO Created by Elizabeth Meyer for "Trees, Shrubs and Conifers" a plant identification course offered in partnership with Longwood Gardens.

More information on Rhododendron.